Microbial community analysis is a technique widely used in order to detect a harmful microorganism existing in an environment, food, and human body. Particularly, in a case of utilizing a 16S rDNA analysis method and a multiple locus strain typing (MLST) method, which are based on microorganism gene amplification through polymerase chain reaction (PCR), in the microbial community analysis, it is possible to obtain more detailed information on the kind of microorganism derived from an environment, food, animals, and human bodies, whether or not the microorganism is mutated, resistance of the microorganism against antibiotics, and the like through high-sensitivity and high-precision genetic analysis. Recently, a technology capable of rapidly performing microbial community analysis on several hundreds of unknown microorganisms collected in various environments using next generation sequencing (NGS) has been known. The microbial community analysis based on gene analysis may have an advantage in that various microorganisms may be simultaneously detected within a short analysis time, but has a limitation in quantitative microbial community analysis. The limitation of gene-based microbial community analysis may be caused by differences in genome extraction and amplification efficiency depending on the microorganism. Particularly, in microbial community analysis based on microorganism 16S rDNA gene amplification, since 16S rDNA gene is amplified using a degenerate primer in order to simultaneously amplify as many kinds of microorganism genes as possible, bias in amplification of genes may be increased depending on the microorganism. The bias in amplification of genes is more clearly observed in a case of precisely analyzing an origin of the gene through NGS. Bias caused by a PCR amplification process is observed in microbial community analysis results through NGS, and it is known that the gene amplification bias is affected by an amplification location, a nucleotide sequence of the primer, or the like.
Therefore, in order to improve accuracy of gene-based quantitative microbial community analysis, a novel technology capable of overcoming the bias in amplification of genes attendant on PCR has been urgently demanded.